Participation of Women in Clinical Trials Supporting FDA Approval of Cardiovascular Drugs

Background: Concerns exist that women are underrepresented in trials of cardiovascular medications.

Objectives: The authors sought to examine women's participation and the reported safety and efficacy by gender for pivotal cardiovascular disease (CVD) trials submitted to the U.S. Food and Drug Administration (FDA) supporting marketing applications.

Methods: On the basis of publicly available FDA reviews, the authors assessed enrollment of women in trials supporting 36 drug approvals from 2005 to 2015. Prevalence-corrected estimates for the participation of women were calculated as the percentage of women among trial participants divided by the percentage of women in the disease population (participation to prevalence ratio [PPR]), with a range between 0.8 and 1.2 reflecting similar representation of women in the trial and disease population. Sex differences in efficacy and safety were assessed.

Results: The proportion of women enrolled ranged from 22% to 81% (mean 46%). The calculated PPR by disease area was within or above the desirable range for atrial fibrillation (0.8 to 1.1), hypertension (0.9), and pulmonary arterial hypertension (1.4); PPR was <0.8 for heart failure (0.5 to 0.6), coronary artery disease (0.6), and acute coronary syndrome/myocardial infarction (0.6). The authors found little indication of clinically meaningful gender differences in efficacy or safety. Gender differences in efficacy or safety were described in labeling for 4 drugs.

Conclusions: Women were well represented in trials of drugs for hypertension and atrial fibrillation, and overrepresented for pulmonary arterial hypertension. Representation of women fell below a PPR of 0.8 for trials in heart failure, coronary artery disease, and acute coronary syndrome. Minimal gender differences in drug efficacy and safety profiles were observed.